BEIJING - China's biggest commercial banks said Wednesday night their major shareholders had vowed not to reduce stock holdings as the country's market rout continues.

The Industrial and Commercial Bank of China and the Agricultural Bank of China said their shareholders - the Ministry of Finance (MOF) and Central Huijin Investment Co Ltd - have given them assurance they will not sell their shares.

Central Huijin promised not to reduce its holdings in China Construction Bank, Bank of China and China Ever Bright Bank, a joint-equity bank.

The MOF vowed not to sell the shares of Bank of Communication.

CITIC Group assured CITIC Bank of not reducing holdings and that it would increase stakes "at an opportune time."

The stock market has taken a nose dive over the last month, with the Shanghai Composite Index shedding more than 30 percent. The financial regulators on Wednesday urged major shareholders to avoid making the situation getting worse by holding the urge to sell.